VDiskFile fixed bug which occurred if two new VDiksFile were created
with the same name
VDiskFile tests added
Changed Exception which was thrown if a File/Directory with the same
name already existed to FileAlreadyExistsException
VDiskFile exist bug fixed
JUnit tests for VDiskFile added
Merge branch 'master' of https://github.com/groggi/eth-jcd.git